I am, yet another, with the dreaded P0171 CEL code. "Tune it out" seems to be a general answer. However, I've seen many with this code that actually had something needing to be fixed/cleaned/replaced. So, I'm going through all options. If anyone has any ideas as to what it could be, please feel free to chime in. I have had the "Torque" android app hooked up to it. Not sure if it's just reading wrong or what but, my f/t 1x2 (which I'm assuming is my LTFT) is reading 99.2% constant. The f/t 1x1 (assuming it's my STFT) is right around 0. With variations up to +-8. I bought both O2 sensors and a fuel filter as a first effort. If I'm able to fix it I will repost saying what the culprit was.

 

try posting this in the correct section problems and service section

 

clean throttle body

 

+1

I used to get P1101 codes all the time whenever I turned the AC on.
Cleaned the throttle body with some walmart brand carb cleaner (remove it first! dont get that crap in the S/C) and no CEL's since

 

i used to get that code, dealer replaced my fuel pump and i havent seen the code again

 

Have you tried taking the intake off and cleaning out the MAF with the spray cleaner? I need to do this on mine. But as they said, cleaning out the TB really good is a quick thing to try.

I've been having this code off and on for a year. I've tried different brands and grades of fuel. In winter I don't ever go WOT so I run 87. I've replaced O2 sensors and still lean bank 1. All I have done to my car is a cone filter airbox mod. Anyone know if a fuel filter could cause this?? I may change it just for giggles.

 

Do you have a tune for your air box mod?^ I know when I bought my car it had a intake, dp and exhaust and I'm guessing the person never had a tune on it and I was throwing the code for a while then I everyone said get a tune so I finally did and the code went away its been 4 months now.

 

Air leak between MAF and throttle body?

 

I don't know about anyone else's vacuum lines but mine are all dried out and cracking. I just got this code for the first time and that is where I'm going to start.

 

jcobaltss, I didn't want to hijack his thread, but I do not have a tune for the airbox mod. UPS is delivering my header and downpipe today actually. And I'll be putting 60#s and a 2.8 pulley on as well so the tune will come after all that. I don't want to eliminate the codes (maybe the post-cat O2) that way I can actually tell if I have an issue.

To the OP, I replaced my silicon cracked hoses and that didn't help me. One thing you can try is getting a can of spray cleaner and spray around cracked hoses and intake clamp areas. If the engine can suck that cleaner into the intake the idle will stumble or surge. I went all around my IM, SC and intake and I had no leaks. It's a tune issue for me.

 

Would a broken flex pipe throw that code? I mean the stock dp are known to blow out but that's if he has stock dp. But everyone giving good info so it could be a lot of different things so just take time and check everything.